During the Japanese colonial era, roughly 400 Korean people, who were forced onto Battleship Island (‘Hashima Island’) to mine for coal, attempt to escape.
In THEORY, the dogs die because the whole island is destroyed but you never see it and the dogs are shown (alive and happy) only for a second earlier in the film.
A woman talks about her traumatizing experiences as a comfort woman (forced prostitute). By the end of the movie every character is deeply traumatized.
A man is shown who is an amputee, he is in a great deal of pain and walks with crutches. He works in the mine, so you can only assume he lost limbs from an accident.
A bathing scene, you don’t see anything, the men are wearing loincloths. The men are forced to strip in another scene and it implies they are cavity searched.
Mentions of Hiroshima. American planes drop small bombs on the island, killing and injuring many. Total destruction, lots of fire. At the end, the survivors view the bombing of Nagasaki from a distance and see the mushroom cloud.